This type of power assisted brakes is the bendix hydromax brakes, which are a typical example of especially suitable for diesel engine vehicles. The system is claimed to be more compact, lighter, permitting lower pedal height and generally faster acting then other available vacuum brake systems.

The two essential parts of the system are the hydromax booster and mini master cylinder. In the hydromax booster, fluid under pressure from the power steering system enters the inlet port, flows through the pressure valve and power Piston, the flow switch, and exits from the return port. When the driver presses the brake pedal, pedal rod is actuated which activates a pressure valve restricting flow through the power Piston. The resulting differential pressure on the power Piston applies force on the master cylinder. The driver gets the feel of braking intensity from the reaction Piston. Pressure regulator limits the maximum boost pressure developed.

The Mini master cylinder has two pressure Chambers primary and secondary, thus providing a fail safe Braking System by tandem operation. Each pressure chamber has a piston/actuator sub assembly containing a caged actuator spring and return Spring. In the released position, actuators of both pistons are in contact with their respective compensating stems, thereby maintaining the valve in open position, which replenishes any fluid displaced from the chambers.

When the brakes are applied via the hydromax booster, the initial forward travel of the primary position causes its actuated to close it's compensating valve. Further movement of the primary Piston then creates a pressure in the primary chamber causing the secondary Piston and actuator to move, there by closing the secondary compensatory valve, shutting off the secondary chamber from the Reservoir. Additional movement of the primary Piston causes both chambers to build pressure, which is transmitted to different wheel cylinders to apply brakes there.

When the brake pedal is released, the load on the primary piston is removed due to which the fluid pressure in each cylinder and the pressure of the return springs cause both the pistons to return to their initial released positions and each actuator opens its respective compensating valve.

In case the normal fluid from the power steering pump is stopped due to any fault, an attached electric pump provides power for reserve stops. In case both the power and reserve systems fail, the brakes can still be applied manually, though with larger force.